Ultrastructural Study of Alterations in the Small Intestinal Epithelium of Children with Acute Diarrhea

We studied the ultrastructure of the jejunal epithelium of six children suffering from acute episodes of gastroenteritis. Ultrastructural alterations of the jejunal mucosa occurred in practically all of the fragments analyzed, although the intensity of the abnormalities observed varied considerably. In most of the patients the alterations were confined to the microvilli, which appeared shortened and tufted in comparison with controls. These Ultrastructural alterations are nonspecific and may represent a general response of the intestinal mucosa against different noxious agents. Severe alteration of the epithelial cells was observed in only one patient. In this case the cytoplasm contained multiple vacuoles that may correspond to dilated endoplasmic reticulum. It is hypothesized that the small intestinal lesions observed in these patients may allow penetration of food antigens, resulting in the appearance of food intolerance frequently described in children suffering from acute diarrhea.